Rahway: Merck, Daiichi Sankyo have announced that Raludotatug deruxtecan (R-DXd) has received Breakthrough Therapy Designation (BTD) from the U.S. Food and Drug Administration (FDA) for the treatment of adult patients with platinum-resistant epithelial ovarian, primary peritoneal or fallopian tube cancers expressing CDH6 who have received prior treatment with bevacizumab. Raludotatug deruxtecan is a specifically engineered, potential first-in-class CDH6 directed DXd antibody drug conjugate (ADC) discovered by Daiichi Sankyo and being jointly developed by Daiichi Sankyo and Merck, known as MSD outside of the United States and Canada. The FDA BTD is designed to accelerate the development and regulatory review of potential new medicines that are intended to treat a serious condition and address a significant unmet medical need. The medicine is required to have shown encouraging preliminary clinical results that demonstrate substantial improvement on a clinically significant endpoint over currently available medicines. The FDA granted this BTD based on data from a phase 1 trial and the ongoing REJOICE-Ovarian01 phase 2/3 trial. A subgroup analysis of the phase 1 trial was presented at the 2023 European Society for Medical Oncology meeting (#ESMO23). Subsequent subgroup analyses of the phase 1 trial were presented at the 2024 Society for Gynecologic Oncology Annual Meeting on Women’s Cancer and the 2025 European Society for Medical Oncology Gynaecological Cancers Congress. This is the first BTD for raludotatug deruxtecan and represents the second BTD since the start of the Daiichi Sankyo and Merck collaboration. “Patients have limited treatment options once ovarian cancer becomes resistant to platinum-based chemotherapy, highlighting the urgent need for new medicines that can improve patient outcomes,” said Ken Takeshita, MD, Global Head, R&D, Daiichi Sankyo. “The receipt of Breakthrough Therapy Designation represents an important step forward in our efforts to advance raludotatug deruxtecan as a novel medicine for patients with CDH6 expressing platinum-resistant ovarian, primary peritoneal, or fallopian tube cancers previously treated with bevacizumab.” “The FDA’s Breakthrough Designation is a reflection of our commitment to advancing research for patients impacted by women’s cancers,” said Eliav Barr, MD, Senior Vice President, Head of Global Clinical Development and Chief Medical Officer, Merck Research Laboratories. “Raludotatug deruxtecan has the potential to one day become an important option for the treatment of patients with CDH6-expressing platinum-resistant ovarian, primary peritoneal, or fallopian tube cancers previously treated with bevacizumab, and we are excited to share data from REJOICE-Ovarian01 with the scientific community at an upcoming medical meeting and to continue working closely with the FDA.”